Mixing plain and polite speech
Most of the time, you will be using polite speech for elder/higher people. However, even when you’re speaking in polite speech, it is customary to introduce some phrases in plain speech. Speaking every phrase in polite speech may sound too stiff for some situations, so that’s why it is actually very important to learn to mix both polite and plain in order for your Japanese to sound more natural.
First of all, let’s suppose you’re talking to an elder with whom you have a pretty close relationship and you aren’t in any particularly formal situation.
In this case, it is normal to use plain speech when you are using interjections for showing your feelings (and like talking to yourself). Some of these are:
That is the most important. Other than that, you must just listen to your heart and…be careful! Don’t forget that it’s always better to be too polite than too rude.
Take a look at this:
This would be acceptable for about 70% of elder Japanese people.
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